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A Consistently Erroneous Technology

James Randi began his career as a stage magician and escape artist but achieved fame as a professional skeptic, disproving the claims of self-described psychics, mind readers, and faith healers. He is a founder of the Committee for Skeptical Inquiry (formerly CSICOP ). Randi’s eleventh book, A Magician in the Laboratory, will be coming out soon.

I’ve often been asked to participate as an advisor in court cases or investigations where I might be useful due to my experience as a con-juror, but I have always refused when required to accept evidence obtained via the polygraph, or lie detector as it’s commonly known. However, if I were to be called upon to deny that this silly device is effective or dependable, I’d have no hesitation in doing so. The evidence is just so much against this technology, it’s difficult to believe how long it has existed as a supposedly valid notion.

Look at the history of so-called “lie detection.” The device itself is a nightmare of tubes, wires, electrodes, and moving styluses, something right out of a Bugs Bunny production. By measuring and displaying changes in the subject’s respiration, heart rate, blood pressure, skin conductivity, and other variables of the human body, a complex series of graph lines is generated, and a technician is—theoretically— able to decide whether the answers to a set of questions were honestly given or not. We need not get into more involved aspects of the procedure such as who comes up with the questions to be asked—though that is a matter of primary importance, of course. Let’s examine opinions of the “professionals” who should know.

About Skeptical Inquirer

Politicization of Scientific Issues:
Looking through Galileo’s Lens or through the
Imaginary Looking Glass
Bigfoot as Big Myth:
Seven Phases of Mythmaking
The Fallacy Fork
Why It’s Time to Get Rid of Fallacy Theory
The Fakery of
Electrodermal Screening